Catalytic dioxygenation of flavonol by M-II-complexes (M = Mn, Fe, Co, Ni, Cu and Zn) - mimicking the M-II-substituted quercetin 2,3-dioxygenase
Catalytic dioxygenation of flavonol by M-II-complexes (M = Mn, Fe, Co, Ni, Cu and Zn) - mimicking the M-II-substituted quercetin 2,3-dioxygenase
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M-II 复合物（M = Mn、Fe、Co、Ni、Cu 和 Zn）催化黄酮醇双加氧 - 模拟 M-II 取代的槲皮素 2,3-双加氧酶
DOI：
10.1039/c5dt01760b
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发表时间：
2015
影响因子：
4
通讯作者：
Sun YJ
中科院分区：
文献类型：
--
作者：
Sun Ying-Ji;Huang Qian-Qian;Li Pei;Zhang Jian-Jun;Sun YJ
为了深入了解金属离子效应和羧酸盐对酶活性的影响，合成了一系列羧酸配体负载的过渡金属配合物[MIIL(OAc)](M=Mn(1)、Fe(2)、Co(3)、Ni(4)、Cu(5)和Zn(6)；Lh=2-{[bis-(pyridin-2-ylmethyl)amino]methyl}-4-methoxy苯甲酸)，并表征了各种MII取代的2，3-双加氧酶(2，3-QD)的结构和功能模型。详细研究了它们的结构、光谱特征、氧化还原性质以及对底物黄酮醇和O2的催化活性。在较低温度(55-100℃)下，模型络合物在底物黄酮醇的催化双氧化(氧化开环)反应中表现出较高的酶活性，这可能是由于支持模型配体上的羧酸基导致的，这可能通过电子供体降低了结合底物黄酮酸酯的氧化还原电位。[MIIL(OAc)]的催化活性有显著差异，其顺序为Co(3)&Gt；Ni(4)&Gt；Zn(6)&Gt；Fe(2)&Gt；Mn(1)&Gt；Cu(5)。它们之间反应活性的差异可以归因于结合底物黄酮酸的氧化还原电势，通过调节黄酮酸的电子密度，金属离子对黄酮酸结合底物的氧化还原电位有很大的影响，这为研究金属离子效应和羧基对不同MII取代的2，3-QD酶活性的影响提供了重要的见解。我们的模型络合物[MIIL(OAc)]是各种MII取代的2，3-QD的一系列结构和功能模型的第一个例子。
In order to get insights into the metal ion effects and the carboxylate effects on enzymatic activity, a series of the carboxylate ligand supported transition metal complexes [MIIL(OAc)] (M = Mn (1), Fe (2), Co (3), Ni (4), Cu (5) and Zn (6); LH = 2-{[bis-(pyridin-2-ylmethyl)amino]methyl}-4-methoxy benzoic acid) were synthesized and characterized as structural and functional models for the active sites of various MII-substituted resting quercetin 2,3-dioxygenases (2,3-QD). Their structures, spectroscopic features, redox properties, as well as the catalytic reactivity toward the substrate flavonol and O2 have been investigated in detail. The model complexes show higher enzymatic reactivities in the catalytic dioxygenation (oxidative ring opening) of the substrate flavonol at lower temperatures (55–100 °C), presumably caused by the carboxylate group in the supporting model ligand, which could lower the redox potential of the bound substrate flavonolate by electron donation. The catalytic reactivity of [MIIL(OAc)] exhibits notable differences and it is in a metal ion dependent order of Co (3) > Ni (4) > Zn (6) > Fe (2) > Mn (1) > Cu (5). The differences in the reactivities among them could be ascribed to the redox potential of the bound substrate flavonolate, which was drastically influenced by the metal ions via tuning the electron density of flavonolate, providing important insights into the metal ion effects and the carboxylate effects on the enzymatic activity of various MII-substituted 2,3-QD. Our model complexes [MIIL(OAc)] are the first examples of a series of structural and functional models of various MII-substituted resting 2,3-QD.